The present invention relates to key duplicating machines, and more particularly, to key duplicating machines which are capable of duplicating single and double-sided keys automatically.
The traditional key duplicating machine was designed to be used by a skilled operator and required many manual steps to complete the key duplication process. Such devices typically included a pair of thumbscrew clamps for clamping the original and blank keys, a gauge for aligning the original and blank keys by fixing the distance between the shoulders of the keys, and a sliding carriage which moved the clamped original and blank keys so that the original key engaged a fixed follower which corresponded to a fixed cutting wheel, so that the cutting wheel would cut a series of teeth in the blank key blade corresponding to the notches in the original.
Such devices permitted error in the alignment of the keys on the clamps, the spacing of keys apart from each other, and the skill of the operator in passing the original key against the follower and effecting a cut in the blank key. Consequently, keys made from such a duplication process possessed a relatively high failure rate.
Attempts have been made to automate such a process and thereby minimize the opportunity for operator error. Once such example is disclosed in Heredia et al. U.S. Pat. No. 5,271,698. That patent discloses a key duplicating machine purportedly capable of duplicating a double-sided key in a single operation, and which includes a pair of horizontally opposed, motor-driven cutter wheels, each mounted on a cutter block which is biased toward the key blank.
A disadvantage with such devices is it is necessary for the operator to force the cutting wheels apart when inserting the original and blank keys into the device; the biasing spring force must be overcome, which may result in misalignment of the key and wear on the cutting wheel. Further, it is necessary for that device to perform every cutting operation in two passes: a first pass away from the cutting machine, and a second pass on a return movement toward the front of the machine. Accordingly, the cutting time to duplicate a particular key is relatively great.
Accordingly, there is a need for a key duplicating machine which facilitates insertion and alignment of the original and blank keys, and which can perform a cutting operation in a single pass, in addition to being safe to operate, uniform in clamping pressure to enhance accuracy of gauging, and which is capable of accepting a wide variety of key shapes.